Re: Chandrayaan 3: Launch and Discussions
Posted: 22 Sep 2023 02:40
Consortium of Indian Defence Websites
https://forums.bharat-rakshak.com/
Sadly, yes - Scott tweeted that no confirmation from CY 3 yet -
"Efforts have been made to establish communication with the Vikram lander and Pragyan rover to ascertain their wake-up condition.
As of now, no signals have been received from them.
Efforts to establish contact will continue.
Thanks for posting.A Nandy wrote: ↑22 Sep 2023 11:55 https://www.youtube.com/watch?v=ewuV1xx_Nrk
Asianet News ‘Dialogues’ with ISRO Chairman S Somanath
FWIW: (My comments with some input from people who know more ) -- The word is that the attempt is going to be continue tomorrow. (The moon has to be visible - for radio antennas in India to send commands to pragyan/Vikaram). It will give more time for Pragyan's electronics to warm up. Word is, Pragyan's components are more likely to survive the winter (as it was easy to test etc) than Vikram's .. but pragyan's has less powerful transmitter .(compared to Vikram-- and much less than PM or CY2)... (People who are more familiar with electronics are more hopeful than I was thinking or they publicly admitted in the past.... but we will know soon -- tomorrow is another day!Amber G. wrote: ↑22 Sep 2023 19:29 Meanwhile: (Now that there is high enough elevation of sun and Vikram and Pragyan is visible from antennas based in India) as I post this.. the ofical word is: ""Efforts have been made to establish communication with the Vikram lander and Pragyan rover to ascertain their wake-up condition.
As of now, no signals have been received from them.
Efforts to establish contact will continue.
They did not announce the sleep/awake, but, that entire cycle was tested on earth.
- "Till now there has been no signal, but I cannot say it will not come up. We can wait the entire lunar day (14 Earth days) as there will be continuous sunlight throughout that period, which means temperature will only go up .." Per Somnathji (ISRO Chairman._
Obviously also (Somanath said):"As long as the temperature is increasing there are chances of systems inside getting warmed up. So the systems could even wake up even on the 14th day, there is no way to predict when it could happen.”
there are multiple advantages to the two systems waking up again, the primary one being the ability to repeat the in situ experiments. ..Many of the experiments we’ve done have given us data but that may change with time. For example, ChaSTE can be put in a new location. If we do one more “hop” we can get a new dataset from another location, which is good…”
“…Because, any consistency of location will not give a true representation of the terrain. If we get more locations, there will be better representation and different characteristics ”
RAMBHA payload would benefit from probing the Moon from a different location and so far as other payloads go, the advantage would be getting data from a different time.
Instruments on Pragyan have already done experiments from multiple locations, but more locations will always be good
From what I know - based on those who know's public and private comments - Also check out Dr. Somnath's statements in the press etc..
At a minimum look up AS9100 certification standards for the aviation industry with regard to electronics manufacturing.
FWIW: (Not an expert on latest electronics, or ISRO's pragyan - but from basic physics and electronics perspective):
Good movie but great book. First bestseller from Crichton.Tanaji wrote: ↑24 Sep 2023 21:24 I was half expecting the scenes from The Andromeda Strain to play out after the OSIRISREx landing…
Link: https://www.newscientist.com/article/23 ... on-lander/
Contrary to the popular expectation I am familiar with the difficulties of extreme cold on electronic components and had written what I had posted earlier....He says that designing craft to survive the vast temperature swings between lunar night and day, which can cause batteries and electrical components to literally crack as they expand and contract, can involve measures like adding radiation sources to provide warmth – but these also add complexity, cost and weight. Often, it is more pragmatic to land a leaner, simpler craft that quickly carries out science before the brutally cold nighttime temperatures destroy it, he says.
“To make sure it can survive is an enormous engineering challenge,” says Cullen. “So quite a few missions will be designed with no serious expectation of surviving the lunar light. And then if, by some chance, you do survive the lunar night, it’s a nice added-on extra.”
“It would seem logical to assume that if it didn’t respond during its second lunar day, then, when it comes to the third lunar day, the chances of responding are significantly less,” he says.
Sarah Casewell at the University of Leicester, UK, says it is now unlikely that the craft will reawaken. “You maybe expect some little bit of delay because things don’t warm up as fast as you’d like or, you know, there’s awkward shadows. But by now, I think you would have expected everything to have warmed up, so it sounds as though the cold was maybe too much.”...
chandran 3 mission India's third lunar
exploration Mission has achieved some
remarkable Feats such as landing on the
moon's South Pole performing a hop
experiment on the lunar surface and
making some amazing discoveries about
the moon's geology and chemistry but
what exactly does this mission mean for
our understanding of the Moon and its
potential for future exploration and
habitation how did the Chandra 3 team
overcome the challenges and difficulties
of landing and roving on the Moon South
Pole what are some of the key findings
that have been made by the chandran 3
Orbiter Lander and Rover in this video
we will answer these questions and more
by looking at some of the latest news
and updates about the chandran 3 mission
so stay tuned and get ready to learn
more about India's amazing moon
The Vikram Lander’s Unplanned Hop Experiment
mission
the first thing we talk about is the
vickram Lander's unplanned hop
experiment on the moon's surface
according to the Project Director Vera
muthuvel this was a surprising and
unexpected event that happened just a
few hours before the lunar night began
the vicam Lander which had successfully
landed on the moon's South Pole on
August 23rd along with the pragian Rover
suddenly lifted off from its Landing
site and flew for about 10 seconds
before landing again at a distance of
about 50 m this was not part of the
original Mission plan but rather a
spontaneous decision made by the Lander
onboard computer so what is a hop
experiment and why did the vicrum Lander
do it a hop experiment is a maneuver
that involves lifting off from one
location on a planetary surface and
landing at another location this can be
done for various reasons such as
1:53
exploring different sites avoiding
1:55
obstacles or testing the performance of
1:57
the spacecraft in this case according to
2:00
the Project Director The Hop experiment
2:02
was done to demonstrate the capability
2:04
of the chandran 3 system to lift off
2:07
from the surface of the Moon which could
2:09
enable future missions to return samples
2:11
from the lunar surface to India he said
2:14
that this was a bonus objective that was
2:16
not planned beforehand but rather
2:18
executed by the Lander's computer based
2:20
on its own analysis of the situation
2:23
this experiment was a remarkable
2:25
achievement for several reasons first of
2:27
all it showed that the vicrum Lander had
2:29
had enough fuel and power to perform
2:31
such a maneuver despite having already
2:33
completed its primary mission objectives
2:35
of landing and deploying the Rover
2:38
secondly it showed that the Lander had a
2:40
high degree of autonomy and intelligence
2:43
as it was able to decide and execute the
2:45
Hop without any human intervention or
2:48
communication thirdly it showed that the
2:50
Lander had a robust navigation and
2:52
guidance system as it was able to
2:54
accurately control its attitude thrust
2:57
and trajectory during the Hop and
3:00
finally this means that the Lander had a
3:02
durable structure and design as it was
3:05
able to withstand the impact of Landing
3:07
twice on the rough and Rocky terrain of
3:09
the lunar South Pole such missions would
3:11
require a spacecraft that can lift off
3:13
from the Moon and rendevu with an
3:15
Orbiter or another spacecraft in lunar
3:17
orbit so this hop experiment
3:20
demonstrated that this could be further
3:21
developed and refined for future
3:23
missions in fact India has already
3:26
announced its plans to launch chandran 4
3:28
in 2026
3:30
which will be a sample return mission
3:32
that will collect rocks and soil from
3:34
different locations on the moon and
3:36
bring them back to Earth for
The Pragyan Rover’s Distance and the Orbiter’s Temperature and Water Measurements
3:43
analysis the second thing we talk about
3:45
is some of the major findings made by
3:47
the chandran 3 mission one of the key
3:50
findings is related to the distance
3:52
covered by the pragian Rover which
3:54
traversed over 100 m on the lunar
3:56
surface before losing contact with the
3:58
Lander this is a remarkable achievement
4:01
considering that the Rover was designed
4:02
to travel only 500 m in its entire
4:06
lifetime it also managed to avoid
4:08
falling into craters or getting stuck on
4:10
rocks thanks to its six- whe design and
4:13
its obstacle avoidance system moreover
4:16
it carried a camera and a laser induced
4:18
breakdown spectroscopy Libs instrument
4:22
which allowed it to take pictures and
4:24
analyze the chemical composition of the
4:26
rocks and soil it encountered another
4:28
key finding made by chandran 3 is
4:31
related to the difference in
4:32
temperatures just above and below the
4:34
lunar surface which could indicate the
4:36
presence of water ice the Orbiter
4:39
infrared spectrometer measured the
4:41
surface temperature of the lunar South
4:43
Pole and found that it varied from minus
4:46
156 to
4:48
-11° C depending on the time of day and
4:52
the angle of sunlight however the
4:54
Lander's thermal probe measured the
4:56
subsurface temperature at a depth of 10
4:58
cm and found that it was much lower
5:01
around - 183° c this suggests that there
5:06
is a layer of insulation between the
5:07
Surface and the subsurface which could
5:10
be caused by water ice which is known to
5:12
exist in some permanently shadowed
5:14
regions of the lunar South Pole where
5:16
sunlight never reaches however chandran
5:20
3 has shown that water ice could also
5:22
exist in regions that receive some
5:24
sunlight but are still cold enough to
5:26
preserve it a third key finding made by
5:29
chandre 3 is related to the detection of
5:32
hydroxy and water molecules on the lunar
5:34
surface the Orbiter infrared
5:37
spectrometer IRS also detected the
5:40
presence of hydroxy and water molecules
5:42
on the lunar surface especially in
5:44
regions where there are fresh craters or
5:46
exposed rocks these molecules could have
5:49
been formed by the interaction of solar
5:51
wind or microm meteorites with the lunar
5:53
minerals or by the release of water from
5:55
the interior of the Moon the presence of
5:58
hydroxy and water molecules on the lunar
6:00
surface is important for several reasons
6:03
first of all it shows that the Moon is
6:05
not a dry and Barren world but rather a
6:07
dynamic and evolving one secondly it
6:10
shows that there is a potential source
6:12
of water for future missions that could
6:14
use it for drinking farming or making
6:16
Rocket
The findings made by previous chandrayaan missions
6:24
Fuel the third thing we talk about here
6:27
is some of the other findings made by
6:29
the sh drean Mission such as the mapping
6:31
of minerals and elements on the lunar
6:33
surface and the identification of
6:35
potential Landing sites for future
6:37
missions the Orbiter carried several
6:39
instruments that were able to perform
6:41
these tasks such as the X-ray
6:44
spectrometer which measured the
6:45
abundance and distribution of elements
6:47
such as magnesium aluminum silicon
6:51
calcium titanium iron sodium and more on
6:55
the lunar surface the Imaging system
6:58
consisted of a high resol ution camera
7:00
or HRC a Terrain mapping camera or TMC
7:04
and a hyperspectral imager the HRC
7:07
captured images of the lunar surface
7:09
with a resolution of 0.5 m per pixel the
7:12
TMC created a 3D map of the lunar
7:15
surface with a resolution of 5 m per
7:18
pixel the HSI captured images of the
7:20
lunar surface in 256 spectral bands from
7:24
visible to near infrared wavelengths the
7:27
synthetic aperture radar as
7:30
which operated in two modes circular
7:32
polarization ratio CPR mode and hybrid
7:36
polarization mode HPM the CPR mode
7:39
measured the ratio of reflected signals
7:42
from different polarizations and
7:44
indicated whether the surface was rough
7:46
or smooth the HPM mode measured the
7:49
phase difference between different
7:51
polarizations and indicated whether the
7:53
surface was coherent or
7:56
incoherent these instruments provided
7:58
valuable information information about
8:00
the lunar surface features composition
8:03
diversity and evolution they also help
8:06
to identify potential Landing sites for
8:08
future missions by looking for Regions
8:11
that are flat smooth coherent rich in
8:15
resources and scientifically interesting
8:18
some of these regions include the
8:20
Schrodinger Basin which is a large
8:22
impact crater near the South Pole that
8:24
has a diameter of about 320 km and a
8:28
depth of about 4 kilm it is one of the
8:31
youngest and best preserved craters on
8:33
the moon and has a complex geology that
8:35
includes Central Peaks Terraces Rings
8:39
faults fractures lava flows ponds domes
8:44
cones pits and vents the 8kin Basin
8:48
which is another large impact crater
8:50
near the South Pole that has a diameter
8:52
of about 2,500 km and a depth of about
8:56
13 km it is one of the the oldest and
9:00
largest craters on the moon and has a
9:02
diverse geology that includes mountains
9:05
valleys Plains Hills ridges craters and
9:09
may it also has a high concentration of
9:12
iron and thorium which could be useful
9:14
for future Mining and energy production
9:17
the Shackleton crater which is a small
9:19
impact crater near the South Pole that
9:21
has a diameter of about 21 km and a
9:24
depth of about 4 km it is located at the
9:28
lunar antipo
9:29
which means that it is always facing
9:31
away from the earth it is also one of
9:33
the coldest places on the moon with
9:35
temperatures as low Asus 230° C It is
9:39
believed to contain large amounts of
9:41
water ice in its permanently shadowed
9:43
regions which could be extracted and
9:45
used for various
Outro
9:49
purposes we have reached the end of this
9:52
video we hope that you have enjoyed this
9:54
video and found it informative and
9:56
interesting if you like this video
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10:28
time
Sulfur in soils near the moon's poles might help astronauts live off the land one day, making these measurements an example of science that enables exploration.
--The measurement of sulfur is interesting to scientists for at least two reasons. First, these findings indicate that the highland soils at the lunar poles could have fundamentally different compositions, compared with highland soils at the lunar equatorial regions. This compositional difference likely comes from the different environmental conditions between the two regions — the poles get less direct sunlight.
Second, these results suggest that there's somehow more sulfur in the polar regions. Sulfur concentrated here could have formed from the exceedingly thin lunar atmosphere.
The polar regions of the moon receive less direct sunlight and, as a result, experience extremely low temperatures compared with the rest of the moon. If the surface temperature falls, below -73 degrees C (-99 degrees F), then sulfur from the lunar atmosphere could collect on the surface in solid form — like frost on a window.
Sulfur at the poles could also have originated from ancient volcanic eruptions occurring on the lunar surface, or from meteorites containing sulfur that struck the surface and vaporized on impact.
For long-lasting space missions, many agencies have thought about building some sort of base on the moon. Astronauts and robots could travel from the south pole base to collect, process, store and use naturally occurring materials like sulfur on the moon — a concept called in-situ resource utilization.
In-situ resource utilization means fewer trips back to Earth to get supplies and more time and energy spent exploring. Using sulfur as a resource, astronauts could build solar cells and batteries that use sulfur, mix up sulfur-based fertilizer and make sulfur-based concrete for construction.
Sulfur-based concrete actually has several benefits compared with the concrete normally used in building projects on Earth.
For one, sulfur-based concrete hardens and becomes strong within hours rather than weeks, and it's more resistant to wear. It also doesn't require water in the mixture, so astronauts could save their valuable water for drinking, crafting breathable oxygen and making rocket fuel.
The Chandrayaan-3 lander, pictured as a bright white spot in the center of the box. The box is 1,108 feet (338 meters) wide. (Image credit: NASA/GSFC/Arizona State University)
While seven missions are currently operating on or around the moon, the lunar south pole region hasn't been studied from the surface before, so Pragyan's new measurements will help planetary scientists understand the geologic history of the moon. It'll also allow lunar scientists like me to ask new questions about how the moon formed and evolved.